DeKalb County's West Nile threat low this summer

Published: Tuesday, June 18, 2013 5:30 a.m. CST

Caption

(Rob Winner – rwinner@shawmedia.com)

Vince Leonforte, environmental health practitioner for the DeKalb County Health Department, collects a mosquito trap Friday near West Dresser and North Annie Glidden roads in DeKalb. The mosquitoes will be ground up and tested for West Nile virus.

DeKALB – Heavy rain and flooding in the spring and early summer may be killing the buzz for carriers of West Nile virus this year.

The season thus far has proven too wet for the house mosquito, which carries the virus that has been present in the United States since 1999. House mosquitoes thrive in hot, dry weather, unlike the more noticeably annoying floodwater mosquitoes, said Greg Maurice, director of environmental health for the DeKalb County Health Department.

West Nile virus has not been detected in DeKalb County mosquitoes this year, but some in Cook and DuPage counties were found carrying the virus in the past two months.

Infections happen through the mosquito’s bite and symptoms appear within three to 14 days, according to the Illinois Department of Health. In a mild case, a person may feel a slight fever or headache. In a more severe case, people will feel a high fever with aches throughout their body. Disorientation, tremors, convulsions can follow. Paralysis or death can happen in severe cases.

Last year, a 59-year-old DeKalb man contracted the virus, and has since recovered, Maurice said. The Illinois Department of Public Health reported 290 human infections last year. A total of 12 people died.

Melaney Arnold, Illinois Department of Public Health spokesperson, said it’s a little difficult to tell if the summer will be hot enough for house mosquitoes to breed. Weather is the biggest indicator of their population growth, she said.

“We haven’t found a lot compared to past years,” Arnold said.

Catch basins or storm drains where water has been sitting for weeks are favored breeding areas for the house mosquito, she said. Steady rainfall helps to flush away mosquito eggs, Maurice said.

The Illinois Department of Public Health tracks cases of West Nile virus by working with county health departments across the state. Maurice said the DeKalb County Health Department monitors the local mosquito population by trapping mosquitoes and testing them. The department will have two traps set up in DeKalb and one in Sycamore.

The traps consist of a rubber tube with a fan attached and stagnant water inside. House mosquitoes are attracted to the water and are sucked into the pipe, where they are then trapped by a net. The net is changed weekly.

Mosquitoes are sorted by breed, and the house mosquitoes identified will be processed through a chemical solution that detects the virus.

Dead birds are also tested, even though humans can only contract the virus from mosquitoes.

“The birds are a good carrier of the virus, and they’re kind of our sentinel to let us know where we potentially have mosquitoes carrying the virus,” Maurice said.

If a county has detected the West Nile virus in their area, the departments may focus their efforts on mosquito control by using larvicide, Arnold said.

Grants are awarded to the county health departments that report West Nile activity in their area in the past three years, Arnold said. The grants are used primarily for surveillance of the virus. But they can are also be used for larvicide along with public outreach and prevention programs she said.

This year, the Illinois Department of Public Health awarded $3.4 million to 90 county health departments for their West Nile virus prevention and control efforts. DeKalb County received $22,069.

The house mosquitoes are most active at dawn and dusk, Maurice said. He recommends people keep their windows and doors in good shape and shut them when not used.

People should look around their house for buckets or flowerpots with stagnant water that need to be emptied, he said. Rain gutters and spouts also can provide breeding grounds for the house mosquito.

Maurice said one of the big misconceptions with the house mosquito is that they breed more in wet weather, like floodwater mosquitoes.

“They really do like the hot, dry weather,” Maurice said. “It’s hard to get the message out when you’re not noticing the nuisance mosquitoes.”

West Nile Virus Prevention

Personal protection

• Use mosquito repellent with DEET in it.

• Wear long sleeves, pants early in the morning and late at night.

• Use mosquito netting when sleeping outdoors or for babies in strollers.